feat: add prefix command

commands_test.go

@@ -341,6 +341,180 @@ func TestReadCmd_ToJsonLong(t *testing.T) {
 	assertResult(t, "2\n", result.Output)
 }
 
+func TestPrefixCmd(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := writeTempYamlFile(content)
+	defer removeTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := runCmd(cmd, fmt.Sprintf("prefix %s d", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `d:
+  b:
+    c: 3
+`
+	assertResult(t, expectedOutput, result.Output)
+}
+
+func TestPrefixCmd_MultiLayer(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := writeTempYamlFile(content)
+	defer removeTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := runCmd(cmd, fmt.Sprintf("prefix %s d.e.f", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `d:
+  e:
+    f:
+      b:
+        c: 3
+`
+	assertResult(t, expectedOutput, result.Output)
+}
+
+func TestPrefixMultiCmd(t *testing.T) {
+	content := `b:
+  c: 3
+---
+apples: great
+`
+	filename := writeTempYamlFile(content)
+	defer removeTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := runCmd(cmd, fmt.Sprintf("prefix %s -d 1 d", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `b:
+  c: 3
+---
+d:
+  apples: great
+`
+	assertResult(t, expectedOutput, result.Output)
+}
+func TestPrefixInvalidDocumentIndexCmd(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := writeTempYamlFile(content)
+	defer removeTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := runCmd(cmd, fmt.Sprintf("prefix %s -df d", filename))
+	if result.Error == nil {
+		t.Error("Expected command to fail due to invalid path")
+	}
+	expectedOutput := `Document index f is not a integer or *: strconv.ParseInt: parsing "f": invalid syntax`
+	assertResult(t, expectedOutput, result.Error.Error())
+}
+
+func TestPrefixBadDocumentIndexCmd(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := writeTempYamlFile(content)
+	defer removeTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := runCmd(cmd, fmt.Sprintf("prefix %s -d 1 d", filename))
+	if result.Error == nil {
+		t.Error("Expected command to fail due to invalid path")
+	}
+	expectedOutput := `Asked to process document index 1 but there are only 1 document(s)`
+	assertResult(t, expectedOutput, result.Error.Error())
+}
+func TestPrefixMultiAllCmd(t *testing.T) {
+	content := `b:
+  c: 3
+---
+apples: great
+`
+	filename := writeTempYamlFile(content)
+	defer removeTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := runCmd(cmd, fmt.Sprintf("prefix %s -d * d", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `d:
+  b:
+    c: 3
+---
+d:
+  apples: great`
+	assertResult(t, expectedOutput, strings.Trim(result.Output, "\n "))
+}
+
+func TestPrefixCmd_Error(t *testing.T) {
+	cmd := getRootCommand()
+	result := runCmd(cmd, "prefix")
+	if result.Error == nil {
+		t.Error("Expected command to fail due to missing arg")
+	}
+	expectedOutput := `Must provide <filename> <prefixed_path>`
+	assertResult(t, expectedOutput, result.Error.Error())
+}
+
+func TestPrefixCmd_ErrorUnreadableFile(t *testing.T) {
+	cmd := getRootCommand()
+	result := runCmd(cmd, "prefix fake-unknown a.b")
+	if result.Error == nil {
+		t.Error("Expected command to fail due to unknown file")
+	}
+	expectedOutput := `open fake-unknown: no such file or directory`
+	assertResult(t, expectedOutput, result.Error.Error())
+}
+
+func TestPrefixCmd_Verbose(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := writeTempYamlFile(content)
+	defer removeTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := runCmd(cmd, fmt.Sprintf("-v prefix %s x", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	expectedOutput := `x:
+  b:
+    c: 3
+`
+	assertResult(t, expectedOutput, result.Output)
+}
+
+func TestPrefixCmd_Inplace(t *testing.T) {
+	content := `b:
+  c: 3
+`
+	filename := writeTempYamlFile(content)
+	defer removeTempYamlFile(filename)
+
+	cmd := getRootCommand()
+	result := runCmd(cmd, fmt.Sprintf("prefix -i %s d", filename))
+	if result.Error != nil {
+		t.Error(result.Error)
+	}
+	gotOutput := readTempYamlFile(filename)
+	expectedOutput := `d:
+  b:
+    c: 3`
+	assertResult(t, expectedOutput, strings.Trim(gotOutput, "\n "))
+}
+
 func TestNewCmd(t *testing.T) {
 	cmd := getRootCommand()
 	result := runCmd(cmd, "new b.c 3")

mkdocs/prefix.md

@@ -0,0 +1,96 @@
+Paths can be prefixed using the 'prefix' command.
+The complete yaml content will be nested inside the new prefix path.
+
+```
+yq p <yaml_file> <path>
+```
+
+### To Stdout
+Given a data1.yaml file of:
+```yaml
+a: simple
+b: [1, 2]
+```
+then
+```bash
+yq p data1.yaml c
+```
+will output:
+```yaml
+c:
+  a: simple
+  b: [1, 2]
+```
+
+### Arbitrary depth
+Given a data1.yaml file of:
+```yaml
+a:
+  b: [1, 2]
+```
+then
+```bash
+yq p data1.yaml c.d
+```
+will output:
+```yaml
+c:
+  d:
+    a:
+      b: [1, 2]
+```
+
+### Updating files in-place
+Given a data1.yaml file of:
+```yaml
+a: simple
+b: [1, 2]
+```
+then
+```bash
+yq p -i data1.yaml c
+```
+will update the data1.yaml file so that the path 'c' is prefixed to all other paths.
+
+### Multiple Documents - update a single document
+Given a data1.yaml file of:
+```yaml
+something: else
+---
+a: simple
+b: cat
+```
+then
+```bash
+yq p -d1 data1.yaml c
+```
+will output:
+```yaml
+something: else
+---
+c:
+  a: simple
+  b: cat
+```
+
+### Multiple Documents - update a single document
+Given a data1.yaml file of:
+```yaml
+something: else
+---
+a: simple
+b: cat
+```
+then
+```bash
+yq p -d'*' data1.yaml c
+```
+will output:
+```yaml
+c:
+  something: else
+---
+c:
+  a: simple
+  b: cat
+```

yq.go

@@ -73,6 +73,7 @@ func newCommandCLI() *cobra.Command {
 	rootCmd.AddCommand(
 		createReadCmd(),
 		createWriteCmd(),
+		createPrefixCmd(),
 		createDeleteCmd(),
 		createNewCmd(),
 		createMergeCmd(),
@@ -137,6 +138,28 @@ a.b.e:
 	return cmdWrite
 }
 
+func createPrefixCmd() *cobra.Command {
+	var cmdWrite = &cobra.Command{
+		Use:     "prefix [yaml_file] [path]",
+		Aliases: []string{"p"},
+		Short:   "yq p [--inplace/-i] [--doc/-d index] sample.yaml a.b.c",
+		Example: `
+yq prefix things.yaml a.b.c
+yq prefix --inplace things.yaml a.b.c
+yq p -i things.yaml a.b.c
+yq p --doc 2 things.yaml a.b.d
+yq p -d2 things.yaml a.b.d
+      `,
+		Long: `Prefixes w.r.t to the yaml file at the given path.
+Outputs to STDOUT unless the inplace flag is used, in which case the file is updated instead.
+`,
+		RunE: prefixProperty,
+	}
+	cmdWrite.PersistentFlags().BoolVarP(&writeInplace, "inplace", "i", false, "update the yaml file inplace")
+	cmdWrite.PersistentFlags().StringVarP(&docIndex, "doc", "d", "0", "process document index number (0 based, * for all documents)")
+	return cmdWrite
+}
+
 func createDeleteCmd() *cobra.Command {
 	var cmdDelete = &cobra.Command{
 		Use:     "delete [yaml_file] [path]",
@@ -394,6 +417,40 @@ func writeProperty(cmd *cobra.Command, args []string) error {
 	return readAndUpdate(cmd.OutOrStdout(), args[0], updateData)
 }
 
+func prefixProperty(cmd *cobra.Command, args []string) error {
+	if len(args) != 2 {
+		return errors.New("Must provide <filename> <prefixed_path>")
+	}
+	var updateAll, docIndexInt, errorParsingDocIndex = parseDocumentIndex()
+	if errorParsingDocIndex != nil {
+		return errorParsingDocIndex
+	}
+
+	var paths = parsePath(args[1])
+
+	// Inverse order
+	for i := len(paths)/2 - 1; i >= 0; i-- {
+		opp := len(paths) - 1 - i
+		paths[i], paths[opp] = paths[opp], paths[i]
+	}
+
+	var updateData = func(dataBucket interface{}, currentIndex int) (interface{}, error) {
+
+		if updateAll || currentIndex == docIndexInt {
+			log.Debugf("Prefixing %v to doc %v", paths, currentIndex)
+			var mapDataBucket = dataBucket
+			for _, key := range paths {
+				nestedBucket := make(map[string]interface{})
+				nestedBucket[key] = mapDataBucket
+				mapDataBucket = nestedBucket
+			}
+			return mapDataBucket, nil
+		}
+		return dataBucket, nil
+	}
+	return readAndUpdate(cmd.OutOrStdout(), args[0], updateData)
+}
+
 func readAndUpdate(stdOut io.Writer, inputFile string, updateData updateDataFn) error {
 	var destination io.Writer
 	var destinationName string